Amide acetal initiated chloral polymerization process

ABSTRACT

Disclosed herein is a process for making chloral homopolymers, and copolymers with, for instance, isocyanates and ketenes, at temperatures between about 0* and 60* C. employing amide acetal initiators, and for making composites thereof with ethylenically unsaturated free-radical catalyzed polymers. The polymers are useful, inter alia, in building-product applications.

United States Patent 1 m1 3,716,522

Blume [4 1 Feb. 13, 1973 541 AMIDE ACETAL INITIATED CHLORAL 3,278,490 10/1966 Rosen et al ..260/67 POLYMERIZATION PROCESS 3,454,527 7/1969 Vogl ..260/67 inventor: Roe C. Blume, Wilmington, Del.

E. l. du Pont de Nemours and Company, Wilmington, Del.

Filed: Nov. 12, 1970 Appl. No; 89,135

Assignee:

US. Cl ..260/64, 260/67 R, 260/67 S,

260/67 UA, 260/79, 260/874 Int. Cl. ..C08g 1/18, C08g 3/00 Field of Search ..260/67 R, 64, 67 S,

[56] References Cited UNITED STATES PATENTS 3,254,052 5/1966 McCain et al. 260/67 Primary Examiner--Wil1iam H. Short Assistant Examiner-L. L. Lee Att0rney.lames A. Costello [5 7] ABSTRACT saturated I free-radical catalyzed polymers. The polymers are useful, inter alia, in building-product applications.

22 Claims, No Drawings AMIDE ACETAL INITIATED CHLORAL POLYMERIZATION PROCESS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention concerns the polymerization of chloral (trichloroacetaldehyde) and the copolymerization thereof with various comonomers, employing amide acetal initiators.

2. Description of the Prior Art Heretofore, the preferred method for polymerizing chloral polymers and copolymers has been a cryotache ns ic polymerization. That process involves mixing a Lewis base anionic catalyst such as an amine, ammonium or phosphonium compound with, say, chloral, chloral/isocyanate or chloral/ -ketene and cooling to a temperature of between about to 78 C. The present method, employing amide acetal initiators, makes it unnecessary to employ such low temperatures. Special advantages are also realized in the area of spun fibers made from the polymers andcopolymers according to the disclosure herein. See, for exempts; US. PatTapplication Ser. No. 886,739, filed Dec. 19, 1969, relating to cryotachensic" polymerization of chloral copolymers.

SUMMARY OF THE INVENTION The novel process of this invention comprises contacting the chloral monomer alone or together with various comonomers, with an effective amount of an amide acetal initiator, at a temperature of between about 0 to 60 C. The amide acetal initiators contemplated to be used herein are those of the formula:

wherein:

R and R are each lower hydrocarbyl, preferably of up to five carbons, or together form a divalent radical, containing four to five chain atoms, which is hydrocarbyl except that up to two hetero atoms can be nitrogen, oxygen, or sulfur,

R and R are each hydrocarbyl, preferably of less than eight carbons, or together form a divalent radical containing two to three chain atoms, or are recurring units having an oxygen and up to eight carbons,

R and R can form divalent hydrocarbyl radicals of two to three carbons, and

R and R can form divalent hydrocarbyl radicals of two to three carbons.

The preferred amide acetals are those of the formula:

wherein:

R is lower alkyl of one to four carbon atoms, and

W', W*, W are hydrogen or lower alkyl.

The polymerization of chloral monomer or chloral together with various other amide acetal initiated monomers taught herein, can be conducted in the presence of one or more ethylenically unsaturated monomers polymerizable by a free-radical catalyst. The process of this invention includes chloral polymerization carried out in the presence of such monomers. Also included is the subsequent step of polymerizing the free-radical initiated monomers.

The polymerization of the free-radical polymerized monomers is conducted in the presence of the chloral polymers or copolymers. A free-radical catalyst is present and activation is generally by heat or irradiation. Activation by heat is conducted at temperatures above about C. until polymerization is at least substantially complete.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The chloral polymerization process generally involves mixing the monomer or monomers with the amide acetal initiator at room temperature or between about 0 to 60 C. The polymerization is preferably carried out at between about 0 to 50 C., for example, by mixing initiator with monomers at 40 to 60 C. and cooling to about 0 C. Lower temperatures can be employed but are not necessary. Higher temperatures than about 60 C. are not preferred because they may promote reactions between initiator and monomer. The amide acetal initiators can be employed at levels of 0.005 to 5 mol percent based on the total charge. Generally, however, 0.015 to 2.5 mol percent is used.

Chloral can be used as the only polymerizable monomer. However, it is preferred that comonomers be employed therewith in amounts of up to about 50 percent of total charge based on molecular weight. Chloral copolymers with, for instance, ketenes, isocyanates, diisocyanates, isothiocyanates and diisothiocyanates generally exhibit better tractability and stability than do chloral polymers alone. For instance, heat stability is best when the chloral copolymer contains about 15 to 20 mole percent of one or more of the non-chloral polymerized monomers described herein. The polymerization process taught herein may also be employed to polymerize small amounts of other comonomers such as formaldehyde, for instance, along with the monomers described above.

It has been found that the copolymers generally contain less of the non-chloral component than would be expected from the amounts and ratios of monomers charged. For instance, when 30 percent of an isocyanate is used with percent of chloral, the copolymer will generally have less than about 20 percent of isocyanate component. This is important in determining what monomer charges to make in order to obtain products of specific copolymer molar percentages. In this connection it has been found that acceptable copolymers of chIoral/p-chlorophenyl isochlorophenylisocyanate.

Some of the monomers suitable for copolymerization with chloral are (ketene) (isocyanato (diisocyanute isothiocyanate) diisothlocyanate) (I wherein: i

' X is selected from the group consisting of oxygen and sulfur;

Z and Z alike or different and separately or jointly, are selected from the group consisting of (l) monovalent groups selected from the group consisting of hydrogen, cyano, lower alkoxycarbonyl, and unsubstituted and substituted hydrocarbyl and hydrocarbyloxy in which any hydrocarbyl moiety is of l to 18 carbon atoms selected from the group consisting of alkyl, cycloalkyl, alkenyl, aryl, ara'lkyl and alltaryl, and any substituent is selected from the group consisting of lower-alkoxy, fluorine, chlorine, bromine, and iodine; and (2) divalent groups selected from alkylene of two to seven carbons; I

Z is selected from the group consisting of nonsubstituted and substituted alkyl, cycloalkyl, and alkenyl of up to 18 carbons, aryl of six to 18 carbons and alkaryl and aralkyl of seven to 24 carbons, any substitution being selected from the group consisting of fluorine, chlorine, bromine, iodine, nitro, cyano, phenylazo, NY OY, SY,

in which Y is lower alkyl or phenyl; and

Z is selected from the group consisting of nonsubstituted and substituted alkylene, alkenylene, alkadienylene, alkarylene, aralkylene, cycloalkylene, alkylenebis-(cycloalkylene), I alkylenebis(arylene), arylene, arylenebis-(alkylene) of up to 18 carbons and anthraquinonylene, any substitution being selected from the group consisting of fluorine, chlorine, bromine, iodine, nitro, cyano, phenylazo, OY, SY,

O EJ-OY, and BNYa,

in which Y is loweralkyl or phenyl.

it should be understood that more than one compound of formulas (I), (ll), or (III) can be polymerized simultaneously with chloral in preparing the polymers of this invention. 4

When the following isocyanates, diisocyanates, isothiocyanates and diisothiocyanates are used in the procedures of the Examples, the corresponding chloral/isocyanate polymers are obtained.

methoxydifluoromethyl isocyanate; I

4-ethylphenyl( 1,1dimethylethyl)isocyanate;

Z-benzolblthien-S-yll methylethyl isocyanate;

l ,5 nathth ylene diisocyanate; p-( bis-( 2- chloroethyl)amino)phenyl isocyanate;

ethoxycarbonylmethyl isocyanate;

3-cyano-l methyl-3,3-diphenylpropyl isocyanate;

o-cyanophenyl isocyanate;

l -d iethylaminol ,2,2-trifluoroethyl isocyanate; acqdiethylphenethyl isocyanate;

heptafluoropropyl isocyanate;

2-iodol indanyl isocyanate;

cis,cis-9,l 2-octadecadienyl isocyanate;

4-phenylanthryl isocyanate;

2,6-anthraquinonylene diisocyanate;

3benzyloxy-4-methoxyphenethyl isocyanate;

l-cyclohexenyl isocyanate;

4 trifluoromethyl isocyanatfe;

l ,2,3,4,4a,9,l10,lOa-octalijidro-lisopropyl-l ,4adimethyl-lphenanthryli socyanate;

2,4,6-triiodophenyt-l isocyanate;

abietyl isocyanate;

6-lluoro-2-pyridyl isocyanate;

styrylisocyanate";

l-phenylvinyl isocyanate;

' l,3-butadienylene diisocyanate;

l-adamantyl isocyanate;

3,3,3-trinitropropyl isocyanate; 2-(phenylthio)ethyl isocyanate;

p-phenylazophenyl isocyanate;

allyl isothiocyanate;

benzyl isothiocyanate;

butyl isocyanatoacetate;

p-bromophenyl isothiocyanate;

I p-butoxyphenylisothiocyanate;

o-chloro-a-phenylbenzyl isothiocyanate; l4-cyanotetradecyl isothiocyanate; cyclohexyl isothiocyanate; cyclooctylisothiocyanate; Z-diethylaminethyl isothiocyanate; 2,2-difluoroethyl isothiocyanate; 2,4-dinitrophenyl isothiocyanate; ethylene diisothiocyanate; p-iodophenyl isothiocyanate; 4-methylthiobutyl isothiocyanate; p-phenylene diisothiocyanate;

Z-pyridyl isothiocyanate;

p-( methylthio)phenyl isothiocyanate; and

'9v-phenanthryl isothiocyanate.

When the following ketenes are used in the procedure of the Examples, the corresponding chloral/ketene addition polymers are obtained:

ketene;

methylketene;

dimethylketene;

phenoxyketene;

p-chlorophenoxyketene;

2,4dichlorophenoxyketene;

2,4,-trichlorophenoxyketene; diphenoxyketene;

bis(p-biphenylyl)ketene;

di-p-tolylketene;

dimesitylketene;

dodecylethylketene;

durylphenylketene;

tetradecylketene;

octadecylketene;

benzylmethylketene;

cyclohexylketene;

dimethyleneketene (carbonylcyclopropane);

tetramethyleneketene (carbonylcyclopentane);

isopropenylketene;

vinylketene;

diallylketene;

7-hexadecenylketene;

( l-naphthyl)phenylketene;

3,3,3-trichloropropylketene;

p-methoxyphenylketene;

dicyanolcetene (carbonylmalononitrile);

(ethoxycarbonyl)ketene'(ethyl 3-oxoacrylate);

and (etho'xycarbonyl)-p-tolylketene (ethyl 3-oxo-2- p-tolylac'rylate).

SPECIFIC EMBODIMENTS The following Examples are illustrative of the invention. They are non-limiting and are included within the broad scope of the invention.

EXAMPLES l to 26 The polymers were prepared as follows: The monomer (or monomers), 0.1 M, was placed in a stoppered -ml. test tube which had been flamed and cooled under N,, warmed to C and the initiator added. The mixture was cooled to 0 C and allowed to polymerize. After 15-24 hr., the product was cracked these Exam nes, unless ame'r'w'i's'aspecmed, the

remainder of the monomer charge is p-chlorophenyl from the sides of the tube by cooling in liquid nitrogen 15 isocyanate.

m'rmmon EX. CIfliiORAf M01. 3? i m no. INITIATQ R n 1 """"a;a"" 615 0H cracks; came;

2 7O 0 O l CH3 CH3 CllQCMe 3 CHQCMQ 3 3 7o 1. CH3 CH3 cm am t 70 0.8 CH3 011 811 em 5 70 0.25 CH3 011 am tBu 6 70 0.1 CH3 CH3 tBu tBu 7 70 0.015 CH3 CH3 tau cm 8 70 0.15 CH3 CH3 CH3 CH3 9 7o 2 CH3 ca; c 11 c 11 10 70 0 .1 CH3 011 011 0 11 cu' c a 11 70 0.25 011 CH3 0 x 0 a l2 {0 O O l CHMeg CHMeg CH2CMe3 CH CMe 13 70 0.5 cs CH3 cn cn 1h 70 0.1 CH3 c11 CHZCMe CHQ 15 0.2 CH3 0H CHZCMe CH 16 70 0.2 0 15 cam,- c11 c CH2 1s 70 0.8 c 11 c 11 cfimre 19 70 2. a u-cne-ciz-cue CH3 :0 70 1.2 N-CMe-CH-CMe 0H CH3 :1 70 0.6 N-CMe-CH-CMe CH3 CH3 :2 60 0.15 rs-cue-ca-cm CH3 011 23 0.6 u-cMe-cu-cne 0x 011 0L6 cu-u-cn-cn c r-i c235 25 7 -07 CH-N-CH-CH 0 x c235 26 ca cu ocu ca CH3 e33 7 "iNifiKToR NAMES Example No. Name -2 dimethyll'ormamide dineopentyl acetal -7 dimethylfurmamide di-t-butyl acetal 8 dimethylformamide dimethyl acetal 9 dimethylformamide diethyl acetal l0 dimethyll'ormamide dibenzyl acetal l1 dimethylformamide dicyclohexyl acetal 10 12 diisopropylformamide dinecpentyl acetal 13 dimethylformamide. cyclic ethylene social (or 2-N,N-dimethylamino-1,S-dioxolane) 14-15 dimethylformamide, cyclic 2,2-dimethyl-l,3- propylene aeetal (or 2-N,N- dimethylamino-S,S-dimethyll ,B-dioxane) I 5 16-18 3-N-dimethylamino-9-N-diethylamino- 2,4,8,10-tetraoxaspiro[5 .5 lundecane 19-23 dimethoxy-3.5-dimethyl-lpyrazolylmethane 24-25 diethoxy-l-pyrrolylmethane 26 dimethoxy-N-morphclinornethane EXAMPLE 27 When 1 mol. percent of 2,3,5,6-tetrahydrooxazola- 5 oxazole of the following formula was used:

wherein for the formula given:

R R and R R are CH,-CH the product obtained by precipitation in hexane had an inherent viscosity of about 0.].

EXAMPLE 28 When 0.015, 0.03, 0.06 and 0.12 mol. percent of the polymeric amide acetal of the following formula was used:

wherein for the formula given:

R and R CH R and R are ((CH O polymer of inherent viscosity of 0.28 to 0.15 resulted.

EXAMPLE 29 When 0.4, 0.8, 1.6 and 3.2 mol. percent of the polymeric amide acetal of the following formula was used: 7 V I his. 7 UH (0 p6 \xn-o-cl (Mm NMe; n

wherein for the given formula:

R and R CH and R and R are the (IMP; V 7 (-ch ctIo- Ch lm recurring units, the polymer obtained had an intrinsic viscosity of between about 0.33 and 0.43.

EXAMPLE 31 To a dry test tube under a nitrogen atmosphere was introduced at 60 C 1.25 ml of chloral, 0.2 ml of diphenyl ketene, 0.1 ml of acetonitrile, and 0.1 mole percent of dimethylformamide neopentyl acetal (see Examples 1-2). The mixture was cooled in an ice bath;polymerization to a gel required about 5-6 seconds. The temperature was maintained at 0 C. for 3 hrs. and 21 C. for 16 hrs. After removal of volatiles by baking, there was obtained a 94-97 percent yield of polymer. It underwent a weight loss of 10 percent at C.ai'ter 9 days.

EXAMPLE 32 A solution of8 ml of toluene, 3 ml of chloral, 0.75 ml of butyl ethyl ketene and 18a! of dimethylformamide neopentyl acetal was cooled to 0. It gelled in about 30 seconds. After 3 hours at 0 the polymer was washed with methanol and dried to give a 25 percent yield of copolymer.

THE lNlTlATORS The amide acetal initiators are obtainable by the synthetic procedures shown in the following equations: A. ROH (MeO) CHNMe. (ROhCHNMe B. R NH (R'OhCHNMe rvo mm HNMe C. R NCHO +COF R NCHF R NCH(OR) o. R NCH0 cocl R NCHCL Ewe '-'R NCH(OR The method of Equation A was used to prepare the amide acetals of Examples l-2, 9-18 and 27-30; Equation B for Example 26; Equation C for Example 8; Equation D for Examples 3-7; and Equation F for Examples 19-25. Alternately, the method of Equation E can be employed to prepare the amide acetals of Example 8 and that of Equation G can be employed to produce the initiators of Examples 24 and 25.

Regarding the pyrazoles useful herein, see also coassigned U. S. Application, filed concurrently herewith in the name of Swiatoslaw Trofimenko, entitled "Alkoxy Pyrazoles," Attorney's Docket No. CR 7069, Described therein, inter alia, are pyrazoles and a process therefor.

The pyrazole of Examples 19 to 23 was prepared in the following manner: 100 g. of 3,6-dimethylpyrazole, 200 g. of trimethyl orthoforrnate and 1 g. of ptoluenesulfonic acid was heated until methanol ceased to distill. Solid K,CO, was added and dimethoxy-3,5-

dimethyl-l-pyrazolylmethane obtained by distillation at 54-60/l.l mm. In a similar manner l-diethoxymethyl-pyrazole (,60/2.5 mm.) was obtained. 1,1- Dimethoxyl -pyrazoll -ylethane and 1,1-dimethoxyl benzylpyrazole resulted from reaction of pyrazole with trimethyl orthoacetate and trimethyl orthobenzoate.

By the substitution of various heterocyclic compounds having hydrogen on nuclear nitrogen, first column below, for the 3,5-dimethylpyrazole, corresponding amide acetals, second column, are prepared:

When other orthoforrnates or orthoesters are substituted for the trimethyl orthoformate, similar dialkoxy-l-heterocycloalkanes or other derivatives are produced. For further discussion, see coassigned U. S. application referred to above.

The polymers and copolymers made according to the process of this invention, employing amide acetal initiators, are particularly useful for making spun fibers. When these initiators are used, and in particular, those from amide acetals having a pyrazolyl group, polymers soluble in dimethyl-formamide, toluene, xylene, chloroform and similar solvents are obtained. The fibers can be dry spun from solutions, for example, in toluene. Spinning of a solution of the chloral polymer dissolved in an aromatic hydrocarbon solvent using a less effective aliphatic solvent gave continuous fibers. Preferred conditions are to spin 8-12' percent chloral/isocyanate copolymer of inherent viscosity 1.6-1.7 in toluene or 20 percent copolymer of inherent viscosity of about 1.0 into ethyl acetate or ethyl acetate/acetone mixtures. The fibers obtained have a modulus of l8g/denier and tensile of 0.5g/denier at 20-100 percent elongation. They are useful in fabrics; that may be subjected to elevated temperatures.

A unique property of the polymers obtained by use of amide acetal initiators is that even those with a high chloral content can be melt pressed into films and similar objects. Homopolymers as well as copolymers containing 12 to 20 percent isocyanate are generally heat formable at about 180 to 250 C. When subjected to temperatures of about C. for extended periods of time, the polymers made according to the process of this invention develop less discoloration and weight loss than polymers prepared by prior art methods.

The chloral polymers and copolymers made herein are particularly useful for providing single-phase composites when combined, according to the teaching of this invention, with addition polymers of polymerized ethylenically unsaturated monomers. For a further discussion of these composites, see coassigned U.S. application Scr. No. 42,877, filed Jun. 2, 1970.

PREPARATION OF COMPOSlTES The novel process of this invention further comprises I the polymerization of a mixture of (l) chloral either alone or, optionally, with 0.5 to 40 mol percent, based on chloral, of a keten e or isocyanate, and an amide acetal initiator, and (2) an ethylenically unsaturated free-radical addition polymerizable monomer (present in an amount less than chloral in a weight basis) with a free-radical polymerization catalyst. Most useful of the latter class of monomers are compounds that are liquids at temperatures above about 50 C. and give high molecular weight solid polymers with a peroxy or azo catalyst. The preferred monomers are acrylic and methacrylic esters of lower alkanols and vinyl esters of lower alkanoic acids, e.g., methyl methacrylate, methyl acrylate, and vinyl acetate.

The following examples further illustrate the preparation of these multi-component polymeric composite compositions:

EXAMPLE A percent, based on EXAMPLE B When the polymerization of Example A was carried out except the amide acetal was dimethylformamide dineopentyl acetal (0.07 ml percent), an opaque colorless sheet was obtained that had an impact value of 0.346.

It has been found that use of formaldehyde in small amounts of from about 1 to mol percent in conjunction with from about 0.5 to 3 mol percent of a diary] ketene, both based on the weight of chloral, gives rapid polymerization and composite polymers of good properties. ln Examples A and B, 6 mol percent of formaldehyde was used, based on chloral.

EXAMPLE C A mixture of 22 ml. ofchloral,

13.8 ml. of methyl methacrylate, and

0.22 g. of azodiisobutyronitrile was cooled to about 20 and 0.1 g. of formaldehyde (from polymeric formaldehyde) was introduced in a gaseous nitrogen stream into the mixture. The mixture was then warmed to 50 with stirring under nitrogen and 50 1.1 of dimethoxy-3 ,5 -dimethyl-1 -pyrazolylmethane added. The mixture was then introduced into a )6 X 4 inch mold and the mold and contents cooled from 5 0 to 0 for 30 minutes then heated to 85 C. for 30 minutes. The polymeric product obtained was colorless. It had an impact (Izod) of 0.429 ft. lbsJin. notch and underwent little discoloration upon exposure to light and moisture. g

EXAMPLE D 25 mg. of azodiisobutyronitrile (free-radical initiator) 2. vol. percent of methyl methacrylate 15.4 ml. of chloral 17.5 ml. of methyl methacrylate i .02 ml. of p-chlorophenyl isocyanate 35 mg. of azodiisobutyronitrile 3. 23 vol. percent of methyl methacrylate 28.8 ml. of chloral 9.4 ml. of methyl methacrylate 1.91 ml. of p-chlorophenyl isocyanate 23 mg. of azodiisobutyronitrile In each case, the amide acetal initiators and the solutions were cooled in an ice bath to effect chloral/isocyanate polymerization. When this polymerization was substantially complete, the ice was allowed to melt and the polymer/monomer/initiator mixtures were warmed to 70 C. for 25 hours and 100 C. for 1 hour to produce composite polymer compositions. Such composite polymer compositions were then isolated.

In certain instances, the methyl methacrylate portion of the single-phase composites has been polymerized not by heating but by irradiation. The irradiation procedure is generally conducted on samples in a quartz cell using light of about 2,537A.

Burning tests conducted on the composites, made as described above, show them to be self-extinguishing when removed from contact with an open flame. Selfextinguishing when removed from contact with an open flame. Self-extinguishing properties improve with an increase in the level of chloral that is present.

All of the polymers made by the process described herein are useful in building-product applications where heat stability and good weatherability are desired and in other applications where self-extinguishing properties are important. Composites are especially useful in building-product applications, either with or without added fillers. Such composites containing about 10 to weight percent of ethylenically unsaturates addition monomer polymerized therein are especially preferred.

The embodiments of the invention inwhich an exclusive property or privilege is claimed are defined as follows:

1. A process for polymerizing chloral monomer together with up to 50 mole percent of at least one comonomer selected from the group consisting of X is selected from the group consisting of oxygen and sulfur;

Z and Z alike or different and separately or jointly, are selected from the group consisting of (l) monovalent groups selected from the group consisting of hydrogen, cyano, lower alkoxycarbonyl, and unsubstituted and substituted hydrocarbyl and hydrocarbyloxy in which any hydrocarbyl moiety is of one to 18 carbon atoms selected from the group consisting of alkyl, cycloalkyl, alkenyl, aryl, aralkyl and alkaryl, and any substituent is selected from the group consisting of lower-alkoxy,

v fluorine, chlorine, bromine, and iodine; and (2) divalent groups selected from alkylene of two to seven carbons;

Z is selected from the group consisting of nonsubstituted and substituted alkyl, cycloalkyl, and alkenyl of up to l8 carbons, aryl of six to 18 carbons and alkaryl and aralkyl of seven to 24 carbons, any substitution being selected from the group consisting of fluorine, chlorine, bromine, iodine, nitro, cyano, phenylazo, NY -OY, --SY,

(i) O a. ll C Y, and -CNYz,

in which Y is lower alkyl or phenyl; and

Z is selected from the group consisting of nonsubstituted and substituted alkylene, alkenylene, alkadienylene, alkarylene, aralkylene, cycloalkylene, alkylenebis(cycloalkylene), alkylenebis(arylene), arylene, arylenebis(alkylene) of up to 18 carbons and anthraquinonylene, any substitution 13 being selected from the group consisting of fluorine, chlorine, bromine, iodine, nitro, cyano, phenylazo, -OY, SY,

in which Y is loweralkyl or phenyl, comprising:

contacting monomer with an amide acetal polymerization initiator in an amount between 0.005 to mol percent based on total charge, at a temperature of between about 0 to 60 C. the initiator having the formula wherein R and R are each lower hydrocarbyl of up to five carbons, or together form a divalent radical, containing four to five chain atoms, which is hydrocarbyl except that up to two hetero atoms can be nitrogen, oxygen, or sulfur,

R and R are each hydrocarbyl of less than eight carbons, or together form a divalent radical containing two to three chain carbon atoms, or are recurring units having an oxygen and up to eight car- R ri d R can form divalent hydrocarbyl radicals of two to three carbons, and

R and R can form divalent hydrocarbyl radicals of two to three carbons.

2. A process according to claim 1, wherein one.

, wherein wherein one wherein one wherein one one wherein: OR

R is lower alkyl of one to four carbon atoms, and

W, W, W are hydrogen or lower alkyl.

9. A process according to claim 1, wherein the monomer charge is about 60-80 mole percent chloral and 20-40 mole percent p-chlorophenyl isocyanate.

10. The process of claim 1, wherein the polymeriza-' tion initiator is dimethylformamide dineopentyl acetal.

11. The process of claim I, wherein the polymerization initiator is dimethoxy-3,5-dimethyl-l-pyrazolylmethane.

12. The process of claim 1, wherein the polymerization initiator is dimethylformamide di-t-butyl acetal.

13. The process of claim 1, wherein the polymerization initiator is dimethylformamide dibenzyl acetal.

14. The process of claim 1, carried out in the presence of an ethylenically unsaturated monomer polymerizable by a free-radical catalyst.

15. The process of claim 1, carried out in the presence of (a) an ethylenically unsaturated monomer polymerizable by a free-radical catalyst and (b) a freeradical catalyst, said monomer present in an amount by weight less than chloral.

16. The process of claim 15, including the step of polymerizing the ethylenically unsaturated monomer.

17. The process of claim 16, wherein the ethylenically unsaturated monomer is methyl methacrylate.

18. The process of claim 16, wherein the ethylenically unsaturated monomer is methyl acrylate.

19. The process of claim 16, wherein the ethylenically unsaturated monomer is vinyl acetate.

20. The process of claim 7, carried out in the presence of (a) an ethylenically unsaturated monomer polymerizable by a free-radical catalyst and (b) a freeradical catalyst, said monomer present in an amount by weight less than chloral.

21. The process of claim 20, including the step of polymerizing the ethylenically unsaturated monomer.

22. The process of claim 21, wherein the ethylenically unsaturated monomer is methyl methacrylate. 

1. A process for polymerizing chloral monomer together with up to 50 mole percent of at least one comonomer selected from the group consisting of
 2. A process according to claim 1, wherein one comonomer is a ketone.
 3. A process according to claim 1, wherein one comonomer is an isocyanate.
 4. A process according to claim 1, wherein one comonomer is an isothiocyanate.
 5. A process according to claim 1, wherein one comonomer is a diisocyanate.
 6. A process according to claim 1, wherein one comonomer is a diisothiocyanate.
 7. A process according to claim 1, wherein chloral is the sole monomer.
 8. A process according to claim 1, wherein the amide acetal initiator is of the formula
 9. A process according to claim 1, wherein the monomer charge is about 60-80 mole percent chloral and 20-40 mole percent p-chlorophenyl isocyanate.
 10. The process of claim 1, wherein the polymerization initiator is dimethylformamide dineopentyl acetal.
 11. The process of claim 1, wherein the polymerization initiator is dimethoxy-3,5-dimethyl-1-pyrazolylmethane.
 12. The process of claim 1, wherein the polymerization initiator is dimethylformamide di-t-butyl acetal.
 13. The process of claim 1, wherein the polymerization initiator is dimethylformamide dibenzyl acetal.
 14. The process of claim 1, carried out in the presence of an ethylenically unsaturated monomer polymerizable by a free-radical catalyst.
 15. The process of claim 1, carried out in the presence of (a) an ethylenically unsaturated monomer polymerizable by a free-radical catalyst and (b) a free-radical catalyst, said monomer present in an amount by weight less than chloral.
 16. The process of claim 15, including the step of polymerizing the ethylenically unsaturated monomer.
 17. The process of claim 16, wherein the ethylenically unsaturated monomer is methyl methacrylate.
 18. The process of claim 16, wherein the ethylenically unsaturated monomer is methyl acrylate.
 19. The process of claim 16, wherein the ethylenically unsaturated monomer is vinyl acetate.
 20. The process of claim 7, carried out in the presence of (a) an ethylenically unsaturated monomer polymerizable by a free-radical catalyst and (b) a free-radical catalyst, said monomer present in an amount by weight less than chloral.
 21. The process of claim 20, including the step of polymerizing the ethylenically unsaturated monomer. 